JPH0723483A - Synchronizing signal transmitter - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency when plural kinds of synchronizing signals are sent. CONSTITUTION:Synchronizing signals A, B, C whose level transits for each period and whose repetitive period of level transition part differs from each other are generated. A level transit part (low level part) of the synchronizing signal is converted into a pulse pattern having a length corresponding to the length of the repetitive period of the synchronizing signal to obtain signals a, b, c. The synchronizing signals after conversion are ORed to be a signal (d). A receiver side counts number of clocks based on each level transition part of the signal (d). The pulse pattern is extracted based on the clock number and converted into the original synchronizing signals A, B, C. Thus, plural synchronizing signals are sent through one signal transmission line and the transmission efficiency is improved. One signal line is enough and the cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous signal transmission device, and more particularly to a synchronous signal transmission device for sending a plurality of types of synchronous signals generated in a package in a private branch exchange to another package.

[0002]

2. Description of the Related Art Generally, in a private branch exchange, three types of synchronizing signals are generated in one package and the generated synchronizing signals are sent to other packages. The synchronization signals are, for example, a PBX synchronization signal, a mobile telephone processing synchronization signal, and other telephone processing synchronization signals.

In the conventional synchronizing signal transmission device, when transmitting the generated synchronizing signal, one transmission line is used.
Only the kind of synchronizing signal could be transmitted.

[0004]

In the above-mentioned conventional sync signal transmission device, since only one kind of sync signal can be transmitted to one transmission line, there are many kinds of sync signals to be transmitted. Will increase the number of transmission lines,
There are disadvantages that the transmission efficiency is poor and the cost is increased due to the increase in signal lines.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a synchronous signal transmission device having a high transmission efficiency.

[0006]

In a synchronizing signal transmission apparatus according to the present invention, a level transition is made every predetermined repetition period and the repetition periods of the level transition parts are different from each other.
Is an integer greater than or equal to 2), and a first conversion means for converting each level transition part of the first to nth synchronization signals into identification information corresponding to the synchronization signal. And a sync signal transmitting means including a sending means for logically adding and sending the converted sync signal, and an extracting means for extracting the identification information from the sent logical sum output.
Synchronization signal receiving means including second conversion means for converting the logical sum output into the first to nth synchronization signals in accordance with the identification information extracted by the extraction means, respectively. And

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a synchronizing signal transmission apparatus according to the present invention. In the figure, a synchronization signal transmission apparatus according to an embodiment of the present invention includes a synchronization signal transmission unit 10 that transmits a synchronization signal and synchronization signal reception units 11 to 13 that receive the synchronization signal from the transmission unit 10. It is configured.

The synchronizing signal transmitter 10 generates three kinds of synchronizing signals A, B and C based on the oscillation output of an oscillator (not shown), and the three kinds of generated synchronizing signals are coded in the encoder L. After being encoded by the encoding units L1 to L3, the multiplexing transmission unit X takes the logical sum and converts it to the multiplexed synchronization signal d.

The synchronizing signals A, B and C are level-changed at predetermined repetition periods, and the repetition periods of the level transition portions are different from each other.

The synchronizing signal receiving section 11 comprises a receiving section Y1 for receiving the multiplexed synchronizing signal and a decoding section M1 for decoding the received synchronizing signal. The synchronization signal receiving unit 12 includes a receiving unit Y2 and a decoding unit M2, and the synchronization signal receiving unit 13 includes a receiving unit Y3 and a decoding unit M3, both of which are similar to the receiving unit 11. It is configured.

In the synchronizing signal transmission apparatus of this embodiment having the above-mentioned structure, three types of synchronizing signals are multiplexed and transmitted by one transmission line, so that the transmission efficiency is improved.

Next, an example of the multiplexing will be described with reference to FIG. In FIG. 2, three types of synchronization signals A, B and C are encoded into synchronization signals a, b and c, and then the logical sum (OR) of the signals a, b and c is taken and multiplexed.
The case where it is sent as the signal d is shown.

The synchronizing signal A in the figure has a repetition period of 125 [μs], which is shorter than that of the signals B and C. Further, the synchronization signal B has a repetition period longer than the signal A and shorter than the signal C, and is 125 × 2 = 250 [μs]. Further, the synchronization signal C has a repetition period longer than that of the signals A and B, and is 125 ×
4 = 500 [μs].

When encoding the synchronizing signals A, B and C,
This is performed by converting each level transition portion (low level portion in the figure) of the synchronization signal into identification information corresponding to the synchronization signal. In this embodiment, the identification information of the synchronization signal A is a pulse pattern having a length of 3 clocks, and the identification information of the synchronization signal B is a length of 4 clocks.
It is assumed that the identification information of the synchronization signal C is a pulse pattern each having a length of 5 clocks. Sync signals A, B,
The signals after conversion of C are the signals a, b and c in the figure. The level transition part may be at a high level.

Since the synchronizing signal A has a short repetition period, its level transition portion is converted into a pulse pattern of 3 clocks having a short length. Next, for the synchronization signal B having a short repetition cycle, the level transition portion is converted into a pulse pattern of 4 clocks, and for the synchronization signal C having the longest repetition cycle, the level transition portion thereof is a pulse pattern of 5 clocks. Is converted to.

That is, each level transition part of the original synchronizing signals A, B and C is converted into a pulse pattern having a length corresponding to the length of the repeating period of the synchronizing signal. Since pulse patterns as identification information different from each other are given to the respective synchronization signals A, B, C, the signals a,
Even if the logical sum of b and c is taken and transmitted as the signal d, the receiving side can correctly extract the synchronizing signal based on the pulse pattern as the identification information.

That is, in this embodiment, the encoding unit L
At 1, each level transition portion of the synchronization signal A is converted into a pulse pattern for 3 clocks to become a signal a. Also,
In the encoding unit L2, each level transition part of the synchronization signal B is converted into a pulse pattern for 4 clocks to be a signal b. Furthermore, each level transition part of the synchronization signal C is converted into a pulse pattern for 5 clocks in the encoding unit L3, and becomes a signal c. The signals a, b and c are logically ORed in the multiplexing transmission section X and transmitted as the signal d.

In the synchronizing signal receivers 11 to 13, the signal d is input to each of the receivers Y1 to Y3. Then, in each receiving unit, the number of clocks is counted for each level transition portion of the signal d. If the result of the count is 3 clocks or more, it can be determined that the level transition portion of the signal a is included in that portion. Also, as a result of the count, 4
If it is equal to or more than the clock, it can be determined that the level transition portion of the signal b is included in that portion, and if it is 5 clocks,
It can be determined that the portion includes the level transition portion of the signal c. Therefore, the signals a, b, and c can be extracted from the signal d by counting the number of clocks in each of the receivers Y1 to Y3. With respect to the extracted signals a, b, and c, the level transition portions are converted back in each of the decoding units M1 to M3. As a result, the synchronization signals A, B and C are transmitted from the decoding units M1 to M3, respectively. Since the decoding process takes time, the synchronization signals A to C are sent from the decoding units M1 to M3 with a delay of one cycle (125 [μs]) from the signals a to c.

In the above embodiment, the synchronization signal A,
Although the length of the pulse pattern serving as identification information is determined according to the length of the B and C repetition periods, various pulse patterns can be adopted without being limited to this. For example, as shown in FIG. 3, the level transition part of the synchronization signal A is converted into a pulse pattern of 3 clocks, the level transition part of the synchronization signal B is converted into a pulse pattern of 4 clocks, and the synchronization signal C is converted into a pulse pattern. The level transition portion may be converted into a pulse pattern of 3 + 1 clocks (there is a blank portion for 3 clocks between them).

Also in this case, the coding units L1 to L3 are also provided.
After the synchronizing signals A to C are converted into respective pulse patterns by the above, the logical sum of the signals a, b and c is taken in the multiplex sending section X and transmitted as the signal d. Then, the signal d is input to each of the receiving units Y1 to Y3 in the synchronization signal receiving unit, and the number of clocks is counted for each level transition portion of the signal d. If the result of the count is 3 clocks or 4 clocks or 3 (4) +1 clocks, it can be determined that the level transition portion of the signal a is included in that portion. If the result of the count is 4 clocks or 4 + 1 clocks, it can be determined that the part includes the level transition part of the signal b, and if it is 3 + 1 clocks or 4 + 1 clocks, the level transition of the signal c is included in that part. It can be determined that the part is included.

Therefore, the signals a, b and c can be extracted from the signal d by counting the number of clocks in each of the receivers Y1 to Y3. With respect to the extracted signals a, b, and c, the level transition portions are converted back in each of the decoding units M1 to M3. As a result, the synchronization signals A, B and C are transmitted from the decoding units M1 to M3, respectively. Since the decoding process takes time, the synchronization signals A to C are sent from the decoding units M1 to M3 with a delay of one cycle (125 [μs]) from the signals a to c.

Furthermore, in the above two embodiments, 3
Each level transition part of each kind of sync signal is individually converted into a pulse pattern, but not limited to this, a pulse pattern corresponding to a combination of sync signals of three kinds of sync signals that make level transitions at the same timing is converted. Examples of conversion are also conceivable. In other words, if there are three types of synchronization signals, there are 7 combinations of synchronization signals that undergo level transitions at the same timing.
Therefore, if each combination is associated with a pulse pattern of 3 bits or more, a plurality of synchronization signals can be transmitted through one transmission path. In this case, the combination of the synchronization signals whose level transits is converted into a pulse pattern and transmitted at each timing of one cycle (125 [μs]).

Here, the type of synchronization signal to be transmitted is n,
Assuming that the number of synchronization signals that make level transitions at the same timing is m, m is an integer and m ≦ n.

As described above, by multiplexing and transmitting a plurality of synchronizing signals, a plurality of synchronizing signals can be transmitted by one signal transmission path. In the above embodiment, the case where there are three types of synchronization signals has been described, but it is obvious that the present invention can be applied to the case where more types of synchronization signals are transmitted. The more types of sync signals, the better the transmission efficiency.

[0026]

As described above, the present invention has an effect that a plurality of synchronizing signals can be transmitted by one signal transmission path by multiplexing and transmitting a plurality of synchronizing signals, thus improving the transmission efficiency. . Moreover, the number of signal lines is only one, and the cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a synchronization signal transmission device according to an embodiment of the present invention.

FIG. 2 is a time chart showing an example of signal waveforms of respective parts in FIG.

FIG. 3 is a time chart showing another example of the signal waveform of each part in FIG.

[Explanation of symbols]

 10 Synchronous signal receiver 11, 12, 13 Synchronous signal transmitter A, B, C Synchronous signal L1, L2, L3 Encoder M1, M2, M3 Decoder

Claims (3)

[Claims] 1. A first to n-th level transition in which a level transition occurs every predetermined repetition period, and the repetition periods of the level transition portions are different from each other.
(N is an integer greater than or equal to 2) Sync signal generating means for generating a sync signal, and a first signal converting each level transition part of the first to nth sync signals into identification information corresponding to the sync signal.
Sync signal transmitting means including a conversion means and a sending means for logically adding and sending the converted sync signal, extracting means for extracting the identification information from the sent logical sum output, and the logical sum. Synchronization signal receiving means including second conversion means for converting the output into the first to nth synchronization signals respectively according to the identification information extracted by the extraction means, and a synchronization signal receiving means. Signal transmission equipment. 2. The synchronization signal transmission device according to claim 1, wherein the identification information is a pulse pattern having a length corresponding to the length of the repetition period of the synchronization signal. 3. The pulse pattern corresponding to a combination of m (m is an integer, and m ≦ n) synchronization signals of which the level transitions at the same timing among the first to nth synchronization signals. 2. The synchronization signal transmission device according to claim 1, wherein